Worldwide sales totaled 68.9 million units in the third quarter of 2016 -- a 5.7 percent drop from the same time last year, according to Gartner. The research firm cited manufacturers' "many challenges," including weak back-to-school demand and lessening appeal among the consumer market, especially in emerging areas.

"There are two fundamental issues that have impacted PC market results: the extension of the lifetime of the PC caused by the excess of consumer devices, and weak PC consumer demand in emerging markets," Mikako Kitagawa, principal Gartner analyst, said in a statement.

Most people own and use at least three different types of devices, she continued, adding that "the PC is not a high priority device for the majority of consumers, so they do not feel the need to upgrade … as often as they used to.

"Some may never decide to upgrade to a PC again," Kitagawa said.

For now, Lenovo is the top PC maker with 20.9 percent of the market, followed closely by HP with 20.4 percent; Dell pulls up the rear with 14.7 percent. But while Lenovo is in the midst of a six-quarter slump, HP and Dell have recorded shipment growth since Q2. Rounding out the top five are Asus (7.8 percent), Apple (7.2 percent) and Acer (6.7 percent). Gartner's data covers desktops, laptops and ultra-mobile (Microsoft Surface) PCs; Chromebooks and iPads were not considered.

And while mobile PCs -- notebooks, 2-in-1s, Windows tablets -- showed single-digit year-over-year growth, the overall results were marred by a decline in desktop shipments, according to Kitagawa.

In the U.S., PC shipments totaled 16.2 million units in the third quarter -- a 0.3 percent decline from the same period last year. "With so many PCs already in the consumer market, U.S. consumers do not feel the need to buy new PCs; many parents hand down old PCs to their kids," Kitagawa said.

The U.S. did, however, see an uptick in Q2 shipments, according to July reports, which tipped the country's growth at almost 5 percent, according to IDC; Gartner suggested a more conservative, but still positive, 1.4 percent.

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Stephanie Mlot

Stephanie began as a PCMag reporter in May 2012. She moved to New York City from Frederick, Md., where she worked for four years as a multimedia reporter at the second-largest daily newspaper in Maryland. She interned at Baltimore magazine...